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The surface magnetism investigation of FeSiB amorphous thin films obtained by evaporation technique
Sensors and Actuators A 129 (2006) 172–175
The surface magnetism investigation of FeSiB amorphous thin films obtained by evaporation technique Maria Neagu a,∗ , M. Dobromir a , G. Popa a , H. Chiriac b , Gh. Singurel a , Cornelia Hison c a “Al. I. Cuza” University, Faculty of Physics, 11 Carol Blvd., Iasi, Romania National Institute of R&D for Technical Physics, 47 Mangeron Blvd., Iasi, Romania c CRS-Coherentia-CNR, Dip.to di Scienze Fisiche, Facolt` a di Ingegneria and PROMETE Spin-off INFM, Universit´a “Federico II”, P.le V. Tecchio 80, 80125 Napoli, Italy b
Received 5 July 2004; received in revised form 20 September 2005; accepted 23 November 2005 Available online 20 January 2006
Abstract Using magneto-optical Kerr effect the surface magnetic properties of as-deposited and thermal/magnetic annealed Fe77.5 Si7.5 B15 amorphous thin films obtained by evaporation technique are investigated. The minimum value of the coercive field for the as-deposited samples was about 350 A/m, while after magnetic annealing its value becomes about 18 A/m. © 2005 Elsevier B.V. All rights reserved. Keywords: Magneto-optical Kerr effect; Amorphous thin films; Hysteresis loop; Coercive force
1. Introduction The soft magnetic amorphous thin films have outstanding magnetic and magnetoelastic properties which make them particularly suitable for a wide range of sensor applications [1–4]. The control of the surface magnetic properties in these materials is very important in order to obtain miniaturised magnetic devices with improved performances. One of the most frequently used techniques for the surface magnetic characterization is based on the magneto-optic Kerr effect (MOKE), which is the interaction between the incident light and the magnetized surface resulting in a rotation of the plane of polarization by an amount proportional to the sample magnetization [1–3,5–8]. According to the phenomenological theory of magneto-optics, the penetration depth of the light is directly proportional to the light wavelength and inversely proportional to the absorption coefficient of the medium. The aim of this paper is to investigate the surface magnetic behaviour of the Fe77.5 Si7.5 B15 amorphous thin films obtained
∗
Corresponding author. Tel.: +40 232 201199; fax: +40 232 201150. E-mail address: [email protected] (M. Neagu).
0924-4247/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2005.11.037
by evaporation technique from the corresponding amorphous ribbons. The influence of the heat treatment and magnetic annealing on the coercive field was also analysed.
2. Experimental The amorphous thin films were prepared by evaporation in vacuum (10−6 Torr) from amorphous ribbons of nominal composition Fe77.5 Si7.5 B15 . Films with thickness in the range 100–300 nm were deposited onto water-cooled glass and silicon substrates. The film thickness was measured by an interferometric method. The amorphous state of the obtained films was examined by X-ray diffraction. The magneto-optical Kerr measurements were taken with an EL X-01R ellipsometer at 632.8 nm laser wavelength, equipped with a pair of Helmholtz coils which provide the biasing magnetic field for the studied samples. For a linearly polarized light, the rotation of the polarization plane (Kerr rotation), and the phase difference between the electrical field components perpendicular and parallel to the incident light plane (Kerr ellipticity), can be used to obtain the surface hysteresis loops of the ferromagnetic samples.
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175
173
Fig. 1. The specific XRD pattern for the as-deposited Fe77.5 Si7.5 B15 thin films.
The variation of the films surface magnetization as function of the applied magnetic field was measured using MOKE in longitudinal geometry. When the longitudinal Kerr effect is used, the rotation of the light polarization is proportional to the sample magnetization parallel to the incident plane of the light. The hysteresis loops were obtained by plotting the Kerr rotation as function of the applied magnetic field. The treatments were made at temperatures between 370 and 390 ◦ C, with and without applied magnetic field. 3. Results and discussion The amorphous nature of the samples was confirmed by the X-ray diffractometry (XRD) using Cu K␣ radiation. The XRD pattern reported in Fig. 1 shows a completely amorphous structure for the as-deposited Fe77.5 Si7.5 B15 thin films. Fig. 2 shows a specific longitudinal Kerr hysteresis loop for the as-deposited amorphous Fe77.5 Si7.5 B15 thin films (300 nm in thickness) on glass substrate. The presented results are for the easy axis of magnetization. The value of the coercive magnetic field is about 380 A/m, while for the thin films deposited on silicon substrate the minimum value of the coercive magnetic field was about 350 A/m. The investigations were conducted on different areas of the samples surface to show the uniformity of the surface magnetic behaviour.
Fig. 2. Longitudinal Kerr hysteresis loops for the as-deposited Fe77.5 Si7.5 B15 amorphous thin films on glass substrate.
Fig. 3. Longitudinal Kerr hysteresis loops for the as-cast Fe77.5 Si7.5 B15 amorphous ribbons with the external magnetic field parallel to the main axis of the sample on: (a) free side; (b) side in contact with the wheel.
The obtained results for the thin films are compared with those corresponding to the precursor amorphous ribbons. Fig. 3 presents the longitudinal Kerr hysteresis loops of the as-cast Fe77.5 Si7.5 B15 amorphous ribbons (30 m thickness and 3 mm width) for the free side (a) as well as the side in contact with the quenching wheel (b). The external magnetic field was applied parallel to the ribbon main axis. The coercive magnetic field value is higher for the ribbon side in contact with the wheel (about 500 A/m) than for the free side (about 300 A/m). This is obviously due to the melt-spinning technique which determines different quenching rates through the material thickness. Analyzing the obtained results, it can be concluded that amorphous thin films with magnetic properties comparable with those corresponding to the amorphous ribbon precursor can be obtained by the evaporation technique. The thermal treatments and the magnetic annealing can determine the important improvement of the magnetic properties of the thin films. In Fig. 4 is shown the longitudinal Kerr hysteresis loop obtained after the heat treatment in vacuum, during 1 h at 390 ◦ C of the film whose surface magnetization was studied in Fig. 2. The value of the coercive magnetic field decreases to
174
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175 [7] P. Vavassori, L. Callegaro, E. Puppin, F. Malizia, F. Ronconi, J. Magn. Magn. Mater. 157/158 (1996) 171–172. [8] C.G. Kim, Y.W. Rheem, C.O. Kim, E.E. Shalyguina, E.A. Ganshina, J. Magn. Magn. Mater. 262 (2003) 412–419.
Biographies Maria Neagu received the B.Sc. and Ph.D. degrees in physics from “Alexandru Ioan Cuza” University of Iasi, Romania, in 1973 and 1995, respectively. Between 1973 and 2001 she was working at the National Institute of Research & Development for Technical Physics Iasi, Department of Magnetic Materials and Devices. Since 2001 she is Associated Professor at “Alexandru Ioan Cuza” University of Iasi, Faculty of Physics, Department of Plasma Physics, Optics and Structure of the Matter. She is interested in the following research topics: magnetostrictive materials and their applications as sensors, magnetooptical measurements and non-destructive control.
Fig. 4. Longitudinal Kerr hysteresis loop for the heat treated (1 h at 390 ◦ C, in vacuum) Fe77.5 Si7.5 B15 thin films.
about 23 A/m after the annealing, due to the structural relaxation. For annealing times greater than 1 h, the influence of the additional time of treatment on the coercive magnetic field is insignificant because the internal stresses in the film are already removed. The magnetic annealing during 1 h, at 390 ◦ C, with a magnetic field of 250 A/m applied in the film plane, leads to a decrease in the coercive magnetic field to about 18 A/m. The obtained results show that for the studied range of sample thickness the coercive magnetic field values are almost the same, independent on the thin film thickness. This is due to the fact that the penetration depth (about 20 nm) is much smaller than the sample thickness. 4. Conclusions Amorphous thin films with surface magnetic properties comparable with those of the amorphous ribbon precursor can be obtained by the evaporation technique. The optimum heat treatment and magnetic annealing are inducing better soft magnetic characteristics, determining a maximum decrease of the coercive magnetic field value by 95% with respect to the as-deposited state. Researches in to the utilization of the obtained amorphous thin films as sensing elements are in progress. References [1] M. Ali, R. Watts, W.J. Karl, M.R.J. Gibbs, J. Magn. Magn. Mater. 190 (1998) 199–204. [2] A.Yu. Toporov, P.I. Nikitin, M.V. Valeiko, A.A. Beloglazov, V.I. Konov, A.M. Chorbanzadeh, A. Perrone, A. Luches, Sens. Actuators A 59 (1997) 323–326. [3] C. Sheawood, A.D. Mattingley, M.R.J. Gibbs, J. Magn. Magn. Mater. 162 (1996) 147–154. [4] H. Chiriac, M. Pletea, E. Hristoforou, Sens. Actuators A 81 (2000) 166–169. [5] R. Krishnan, M. Tessier, M.C. Contreras, I. Iglesias, IEEE Trans. Magn. 28 (1992) 2427–2429. [6] J. Zak, E.R. Moog, C. Liu, S.D. Bader, J. Appl. Phys. 68 (8) (1990) 4203–4207.
Marius Dobromir was born in 1978, in Vinderei/Vaslui-Romania. He received the B.Sc. and M.Sc. degrees in physics at “Alexandru Ioan Cuza” University of Iasi, Romania, in 2001 and 2003, respectively. Since 2003 he is Ph.D. student at “Alexandru Ioan Cuza” University, Faculty of Physics, Department of Plasma Physics, Optics and Structure of the Matter. He is working in the field of preparation and characterization of magnetic thin films. Gheorghe Popa was born in 1943, in Lucacesti, Romania. He received the Diploma (M.S.) degree in physics from “Alexandru Ioan Cuza” University of Iasi, Romania in 1966 and his Ph.D. in physics, in 1974, in the same University. Since 1966 he is employed in Faculty of Physics of “Alexandru Ioan Cuza” University and promoted in all academic steps until 1990 when he was nominated as Full Professor. He was invited as guest researcher and Professor in plasma physics at University of Innsbruck, Austria, Shizuoka University and Nagoya Institute of Technology, Japan, University of Nantes, France. He worked on the research in plasma discharges and their applications as ion-nitridation, plasma polymerization, surface treatment of polymers and thin layer deposition. He made also fundamental research in Q-machine and D.P. machine plasma on: ionization waves, ion acoustic waves and soliton, ion space charge instabilities and ion cyclotron waves and instabilities. He developed methods for plasma diagnostics. Professor Popa is member of European Physical Society and IOP fellow. Horia Chiriac received the B.Sc. and Ph.D. degrees in physics from the “Alexandru Ioan Cuza” University of Iasi, Romania. Currently he is Director of the National Institute of Research and Development for Technical Physics, Iasi and Associate Professor in physics and Ph.D. supervisor at “Alexandru Ioan Cuza” University of Iasi. His research topics are: production and characterization of amorphous and nanocrystalline magnetic materials as ribbons, wires and glass covered wires, thin films and powders (micro and nanopowders); production and study of the bulk amorphous materials with soft and hard magnetic properties; theoretical studies on the correlation between the preparation conditions of amorphous and nanocrystalline metallic materials and their magnetic properties; theoretical models for explanation of magnetisation processes, magnetoelastic properties and new magnetic phenomenon in amorhous and nanocrystalline magnetic materials as ribbons, wires and glass covered wires; physical properties (i.e. viscosity, surface tension) of the amorphous alloys in liquid state; studies on new types of magnetic sensors and transducers based on amorphous and nanocrystalline magnetic materials as ribbons and wires. Ghita Singurel was born in 1937 in Soveja/Vrancea-Romania. He received the B.Sc. degree in physics from “Alexandru Ioan Cuza” University of Iasi, Romania in 1959, and Ph.D. degree in physics (Lasers and Nonlinear Optics) from M.V. LOMONOSOV University of Moscow-Russia in 1969. Since 1994 he is Professor at “Alexandru Ioan Cuza” University, Faculty of Physics. He is interested in the following research topics: Quantum optics (Interaction of laser radiation with matter), Optics (magneto-optics and optics of turbid media), Molecular Spectroscopy (Fluorescence, IR Spectroscopy of Polymers, Molecular Interactions, 2D Correlation Spectroscopy).
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175 Cornelia Hison received the Diploma Engineering degree in technical physics from the “Alexandru Ioan Cuza” University of Iasi, Romania in 1995, and the M.Sc. degree in physics of plasma and spectroscopy and Ph.D. degree in Physics from the same University in 1996 and 2004, respectively. Between 1995–2001 she was scientific researcher at National Institute of Research &
175
Development for Technical Physics, Iasi, Romania. Since 2001 she is joining Naples Magnetism Group of the Italian National Institute for the Physics of Matter (INFM) working in the field of production and characterization of magnetoelastic materials and elastomagnetic composites and their application as sensors and actuators; theoretical studies on elastomagnetism.
The surface magnetism investigation of FeSiB amorphous thin films obtained by evaporation technique Maria Neagu a,∗ , M. Dobromir a , G. Popa a , H. Chiriac b , Gh. Singurel a , Cornelia Hison c a “Al. I. Cuza” University, Faculty of Physics, 11 Carol Blvd., Iasi, Romania National Institute of R&D for Technical Physics, 47 Mangeron Blvd., Iasi, Romania c CRS-Coherentia-CNR, Dip.to di Scienze Fisiche, Facolt` a di Ingegneria and PROMETE Spin-off INFM, Universit´a “Federico II”, P.le V. Tecchio 80, 80125 Napoli, Italy b
Received 5 July 2004; received in revised form 20 September 2005; accepted 23 November 2005 Available online 20 January 2006
Abstract Using magneto-optical Kerr effect the surface magnetic properties of as-deposited and thermal/magnetic annealed Fe77.5 Si7.5 B15 amorphous thin films obtained by evaporation technique are investigated. The minimum value of the coercive field for the as-deposited samples was about 350 A/m, while after magnetic annealing its value becomes about 18 A/m. © 2005 Elsevier B.V. All rights reserved. Keywords: Magneto-optical Kerr effect; Amorphous thin films; Hysteresis loop; Coercive force
1. Introduction The soft magnetic amorphous thin films have outstanding magnetic and magnetoelastic properties which make them particularly suitable for a wide range of sensor applications [1–4]. The control of the surface magnetic properties in these materials is very important in order to obtain miniaturised magnetic devices with improved performances. One of the most frequently used techniques for the surface magnetic characterization is based on the magneto-optic Kerr effect (MOKE), which is the interaction between the incident light and the magnetized surface resulting in a rotation of the plane of polarization by an amount proportional to the sample magnetization [1–3,5–8]. According to the phenomenological theory of magneto-optics, the penetration depth of the light is directly proportional to the light wavelength and inversely proportional to the absorption coefficient of the medium. The aim of this paper is to investigate the surface magnetic behaviour of the Fe77.5 Si7.5 B15 amorphous thin films obtained
∗
Corresponding author. Tel.: +40 232 201199; fax: +40 232 201150. E-mail address: [email protected] (M. Neagu).
0924-4247/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2005.11.037
by evaporation technique from the corresponding amorphous ribbons. The influence of the heat treatment and magnetic annealing on the coercive field was also analysed.
2. Experimental The amorphous thin films were prepared by evaporation in vacuum (10−6 Torr) from amorphous ribbons of nominal composition Fe77.5 Si7.5 B15 . Films with thickness in the range 100–300 nm were deposited onto water-cooled glass and silicon substrates. The film thickness was measured by an interferometric method. The amorphous state of the obtained films was examined by X-ray diffraction. The magneto-optical Kerr measurements were taken with an EL X-01R ellipsometer at 632.8 nm laser wavelength, equipped with a pair of Helmholtz coils which provide the biasing magnetic field for the studied samples. For a linearly polarized light, the rotation of the polarization plane (Kerr rotation), and the phase difference between the electrical field components perpendicular and parallel to the incident light plane (Kerr ellipticity), can be used to obtain the surface hysteresis loops of the ferromagnetic samples.
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175
173
Fig. 1. The specific XRD pattern for the as-deposited Fe77.5 Si7.5 B15 thin films.
The variation of the films surface magnetization as function of the applied magnetic field was measured using MOKE in longitudinal geometry. When the longitudinal Kerr effect is used, the rotation of the light polarization is proportional to the sample magnetization parallel to the incident plane of the light. The hysteresis loops were obtained by plotting the Kerr rotation as function of the applied magnetic field. The treatments were made at temperatures between 370 and 390 ◦ C, with and without applied magnetic field. 3. Results and discussion The amorphous nature of the samples was confirmed by the X-ray diffractometry (XRD) using Cu K␣ radiation. The XRD pattern reported in Fig. 1 shows a completely amorphous structure for the as-deposited Fe77.5 Si7.5 B15 thin films. Fig. 2 shows a specific longitudinal Kerr hysteresis loop for the as-deposited amorphous Fe77.5 Si7.5 B15 thin films (300 nm in thickness) on glass substrate. The presented results are for the easy axis of magnetization. The value of the coercive magnetic field is about 380 A/m, while for the thin films deposited on silicon substrate the minimum value of the coercive magnetic field was about 350 A/m. The investigations were conducted on different areas of the samples surface to show the uniformity of the surface magnetic behaviour.
Fig. 2. Longitudinal Kerr hysteresis loops for the as-deposited Fe77.5 Si7.5 B15 amorphous thin films on glass substrate.
Fig. 3. Longitudinal Kerr hysteresis loops for the as-cast Fe77.5 Si7.5 B15 amorphous ribbons with the external magnetic field parallel to the main axis of the sample on: (a) free side; (b) side in contact with the wheel.
The obtained results for the thin films are compared with those corresponding to the precursor amorphous ribbons. Fig. 3 presents the longitudinal Kerr hysteresis loops of the as-cast Fe77.5 Si7.5 B15 amorphous ribbons (30 m thickness and 3 mm width) for the free side (a) as well as the side in contact with the quenching wheel (b). The external magnetic field was applied parallel to the ribbon main axis. The coercive magnetic field value is higher for the ribbon side in contact with the wheel (about 500 A/m) than for the free side (about 300 A/m). This is obviously due to the melt-spinning technique which determines different quenching rates through the material thickness. Analyzing the obtained results, it can be concluded that amorphous thin films with magnetic properties comparable with those corresponding to the amorphous ribbon precursor can be obtained by the evaporation technique. The thermal treatments and the magnetic annealing can determine the important improvement of the magnetic properties of the thin films. In Fig. 4 is shown the longitudinal Kerr hysteresis loop obtained after the heat treatment in vacuum, during 1 h at 390 ◦ C of the film whose surface magnetization was studied in Fig. 2. The value of the coercive magnetic field decreases to
174
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175 [7] P. Vavassori, L. Callegaro, E. Puppin, F. Malizia, F. Ronconi, J. Magn. Magn. Mater. 157/158 (1996) 171–172. [8] C.G. Kim, Y.W. Rheem, C.O. Kim, E.E. Shalyguina, E.A. Ganshina, J. Magn. Magn. Mater. 262 (2003) 412–419.
Biographies Maria Neagu received the B.Sc. and Ph.D. degrees in physics from “Alexandru Ioan Cuza” University of Iasi, Romania, in 1973 and 1995, respectively. Between 1973 and 2001 she was working at the National Institute of Research & Development for Technical Physics Iasi, Department of Magnetic Materials and Devices. Since 2001 she is Associated Professor at “Alexandru Ioan Cuza” University of Iasi, Faculty of Physics, Department of Plasma Physics, Optics and Structure of the Matter. She is interested in the following research topics: magnetostrictive materials and their applications as sensors, magnetooptical measurements and non-destructive control.
Fig. 4. Longitudinal Kerr hysteresis loop for the heat treated (1 h at 390 ◦ C, in vacuum) Fe77.5 Si7.5 B15 thin films.
about 23 A/m after the annealing, due to the structural relaxation. For annealing times greater than 1 h, the influence of the additional time of treatment on the coercive magnetic field is insignificant because the internal stresses in the film are already removed. The magnetic annealing during 1 h, at 390 ◦ C, with a magnetic field of 250 A/m applied in the film plane, leads to a decrease in the coercive magnetic field to about 18 A/m. The obtained results show that for the studied range of sample thickness the coercive magnetic field values are almost the same, independent on the thin film thickness. This is due to the fact that the penetration depth (about 20 nm) is much smaller than the sample thickness. 4. Conclusions Amorphous thin films with surface magnetic properties comparable with those of the amorphous ribbon precursor can be obtained by the evaporation technique. The optimum heat treatment and magnetic annealing are inducing better soft magnetic characteristics, determining a maximum decrease of the coercive magnetic field value by 95% with respect to the as-deposited state. Researches in to the utilization of the obtained amorphous thin films as sensing elements are in progress. References [1] M. Ali, R. Watts, W.J. Karl, M.R.J. Gibbs, J. Magn. Magn. Mater. 190 (1998) 199–204. [2] A.Yu. Toporov, P.I. Nikitin, M.V. Valeiko, A.A. Beloglazov, V.I. Konov, A.M. Chorbanzadeh, A. Perrone, A. Luches, Sens. Actuators A 59 (1997) 323–326. [3] C. Sheawood, A.D. Mattingley, M.R.J. Gibbs, J. Magn. Magn. Mater. 162 (1996) 147–154. [4] H. Chiriac, M. Pletea, E. Hristoforou, Sens. Actuators A 81 (2000) 166–169. [5] R. Krishnan, M. Tessier, M.C. Contreras, I. Iglesias, IEEE Trans. Magn. 28 (1992) 2427–2429. [6] J. Zak, E.R. Moog, C. Liu, S.D. Bader, J. Appl. Phys. 68 (8) (1990) 4203–4207.
Marius Dobromir was born in 1978, in Vinderei/Vaslui-Romania. He received the B.Sc. and M.Sc. degrees in physics at “Alexandru Ioan Cuza” University of Iasi, Romania, in 2001 and 2003, respectively. Since 2003 he is Ph.D. student at “Alexandru Ioan Cuza” University, Faculty of Physics, Department of Plasma Physics, Optics and Structure of the Matter. He is working in the field of preparation and characterization of magnetic thin films. Gheorghe Popa was born in 1943, in Lucacesti, Romania. He received the Diploma (M.S.) degree in physics from “Alexandru Ioan Cuza” University of Iasi, Romania in 1966 and his Ph.D. in physics, in 1974, in the same University. Since 1966 he is employed in Faculty of Physics of “Alexandru Ioan Cuza” University and promoted in all academic steps until 1990 when he was nominated as Full Professor. He was invited as guest researcher and Professor in plasma physics at University of Innsbruck, Austria, Shizuoka University and Nagoya Institute of Technology, Japan, University of Nantes, France. He worked on the research in plasma discharges and their applications as ion-nitridation, plasma polymerization, surface treatment of polymers and thin layer deposition. He made also fundamental research in Q-machine and D.P. machine plasma on: ionization waves, ion acoustic waves and soliton, ion space charge instabilities and ion cyclotron waves and instabilities. He developed methods for plasma diagnostics. Professor Popa is member of European Physical Society and IOP fellow. Horia Chiriac received the B.Sc. and Ph.D. degrees in physics from the “Alexandru Ioan Cuza” University of Iasi, Romania. Currently he is Director of the National Institute of Research and Development for Technical Physics, Iasi and Associate Professor in physics and Ph.D. supervisor at “Alexandru Ioan Cuza” University of Iasi. His research topics are: production and characterization of amorphous and nanocrystalline magnetic materials as ribbons, wires and glass covered wires, thin films and powders (micro and nanopowders); production and study of the bulk amorphous materials with soft and hard magnetic properties; theoretical studies on the correlation between the preparation conditions of amorphous and nanocrystalline metallic materials and their magnetic properties; theoretical models for explanation of magnetisation processes, magnetoelastic properties and new magnetic phenomenon in amorhous and nanocrystalline magnetic materials as ribbons, wires and glass covered wires; physical properties (i.e. viscosity, surface tension) of the amorphous alloys in liquid state; studies on new types of magnetic sensors and transducers based on amorphous and nanocrystalline magnetic materials as ribbons and wires. Ghita Singurel was born in 1937 in Soveja/Vrancea-Romania. He received the B.Sc. degree in physics from “Alexandru Ioan Cuza” University of Iasi, Romania in 1959, and Ph.D. degree in physics (Lasers and Nonlinear Optics) from M.V. LOMONOSOV University of Moscow-Russia in 1969. Since 1994 he is Professor at “Alexandru Ioan Cuza” University, Faculty of Physics. He is interested in the following research topics: Quantum optics (Interaction of laser radiation with matter), Optics (magneto-optics and optics of turbid media), Molecular Spectroscopy (Fluorescence, IR Spectroscopy of Polymers, Molecular Interactions, 2D Correlation Spectroscopy).
M. Neagu et al. / Sensors and Actuators A 129 (2006) 172–175 Cornelia Hison received the Diploma Engineering degree in technical physics from the “Alexandru Ioan Cuza” University of Iasi, Romania in 1995, and the M.Sc. degree in physics of plasma and spectroscopy and Ph.D. degree in Physics from the same University in 1996 and 2004, respectively. Between 1995–2001 she was scientific researcher at National Institute of Research &
175
Development for Technical Physics, Iasi, Romania. Since 2001 she is joining Naples Magnetism Group of the Italian National Institute for the Physics of Matter (INFM) working in the field of production and characterization of magnetoelastic materials and elastomagnetic composites and their application as sensors and actuators; theoretical studies on elastomagnetism.